org.apache.jackrabbit.oak.plugins.document

Class FormatVersion

java.lang.Object

org.apache.jackrabbit.oak.plugins.document.FormatVersion

All Implemented Interfaces:

Comparable<FormatVersion>

public final class FormatVersion
extends Object
implements Comparable<FormatVersion>

The format version currently in use by the DocumentNodeStore and written to the underlying DocumentStore. A version canRead(org.apache.jackrabbit.oak.plugins.document.FormatVersion) the current or older versions.

Method Summary

Modifier and Type	Method and Description
boolean	canRead(FormatVersion other) Returns true if this version can read data written by the other version.
int	compareTo(@NotNull FormatVersion other)
boolean	equals(Object obj)
String	toString()
static FormatVersion	valueOf(String s) Returns a format version for the given String representation.
static Iterable<FormatVersion>	values()
static @NotNull FormatVersion	versionOf(@NotNull DocumentStore store) Reads the FormatVersion from the given store.
boolean	writeTo(@NotNull DocumentStore store) Writes this version to the given document store.

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Detail

values

public static Iterable<FormatVersion> values()

Returns:

well known format versions.

canRead

public boolean canRead(FormatVersion other)

Returns true if this version can read data written by the other version.

Parameters:

other - the version the data was written in.

Returns:

true if this version can read, false otherwise.

versionOf

@NotNull
public static @NotNull FormatVersion versionOf(@NotNull
                                                        @NotNull DocumentStore store)
                                                 throws DocumentStoreException

Reads the FormatVersion from the given store. This method returns V0 if the store currently does not have a version set.

Parameters:

store - the store to read from.

Returns:

the format version of the store.

Throws:

DocumentStoreException - if an error occurs while reading from the store.

writeTo

public boolean writeTo(@NotNull
                       @NotNull DocumentStore store)
                throws DocumentStoreException

Writes this version to the given document store. The write operation will fail with a DocumentStoreException if the version change is considered incompatible or cannot be applied for some other reason. This includes:

• An attempt to downgrade the existing version
• There are active cluster nodes using an existing version
• The version was changed concurrently

Parameters:

store - the document store.

Returns:

true if the version in the store was updated, false otherwise. This method will also return false if the version in the store equals this version and now update was required.

Throws:

DocumentStoreException - if the write operation fails. Reasons include: 1) an attempt to downgrade the existing version, 2) there are active cluster nodes using an existing version, 3) the version was changed concurrently.

valueOf

public static FormatVersion valueOf(String s)
                             throws IllegalArgumentException

Returns a format version for the given String representation. This method either returns one of the well known versions or an entirely new version if the version is not well known.

Parameters:

s - the String representation of a format version.

Returns:

the parsed format version.

Throws:

IllegalArgumentException - if the string is malformed.

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

compareTo

public int compareTo(@NotNull
                     @NotNull FormatVersion other)

Specified by:

compareTo in interface Comparable<FormatVersion>